added performance measurement for font-size and line-height adjust at pagination time, see https://github.com/readium/readium-shared-js/issues/274
added performance measurement for font-size and line-height adjust at
pagination time, see
https://github.com/readium/readium-shared-js/issues/274

NYPL-Simplified/readium-shared-js,kivuto/readium-shared-js,readium/readium-shared-js,NYPL-Simplified/readium-shared-js,readium/readium-shared-js,NYPL/readium-shared-js,ravn-no/readium-shared-js,JoMedia/readium-shared-js,kivuto/readium-shared-js,NYPL/readium-shared-js,ravn-no/readium-shared-js